What are the most important numbers for me to consider at when looking at quotes? I'm in the market for a system in western Worcester, Mass and have a bunch of quotes to go through. How can I narrow them down to only the best ones?

With a lease/PPA, you'll want to look at monthly savings. If you purchase your system, you'll want to look at the cost of the system (usually dollars-per-watt, or $/W) and at payback times and return on investment. In both instances, you can use levelized cost of energy (LCOE) to compare the actual rates you'll be paying for solar over (for example) a 20-year period.

Once you've determined which deals offer the best value, then you can start getting into other questions about installer history, reputation and expertise and the quality of the components being used. If you're interested in learning more, check out our recent article: What questions should you ask your solar installer?